<i>In vitro</i> clonal multiplication of an apple rootstock by culture of shoot apices and axillary buds

Abstract

<i>In vitro</i> clonal multiplication of apple rootstock M M 111 using axillary buds and shoot apices were carried out. Vegetative axillary buds of the size of 0.2-2.0 cm and shoot apices measuring 4 mm in length were initiated to shoot proliferation on MS medium supplemented with BA (0.5-1.0 mgl^-1), GA₃(0.5 mgl^-1), with or without IBA (0.05-0.1 mgl^-1). Small size ex plants showed less phenol exudation and less contamination. Following establishment phase, the small shoots emerged from explants were subcultured on M S medium supplemented with different combinations and concentrations of growth regulators. B A (1.0 mgl^-1) and GA₃(0.5 mgl^-1) combination showed highest multiplication rate (1:5) , and also produced longer shoots. Two step rooting was done by transferring microcuttings to auxin free solid medium after root initiation in dark on 1/2 strength M S liquid medium containing IBA (0.5 GA₃(0.5 mgl^-1). Rooted plantlets were transferred to peat containing paper cups and resulting plants of MM 111 acclimated successfully for transfer to field.